1. Field of the Invention
The invention relates to a compound or salts thereof suitable for use as a binder for mineral fibres, i.e. men made vitreous fibres (MMVF), for example glass slag or stone wool, i.e. mineral wool, in particular Rockwool, a binder composition comprising such a compound, a process for providing said compound and composition, a mineral fibre product provided with such a binder and the use of said compound and composition as a mineral fibre binder.
2. Description of the Related Art
Phenol and formaldehyde resins which are mainly used as binders for glass or stonewool release toxic substances during curing, for example formaldehyde.
During application and curing of the binders, after provision thereof to the mineral fibres, phenol, formaldehyde and ammonia are released. From an environmental point of view this is undesirable.
Furthermore during application, mostly by spraying, of the binder onto the spun glass or stone fibres a large amount of binder is lost, which is almost impossible to recover for re-use.
A formaldehyde and phenol free resin suitable for a binder for mineral wool fibres is described in the patent application PCT/NL99/00029 from the applicant.
According to a first aspect of the present invention there is provided a resin for a binder suitable for mineral fibers such as glass or stone wool.
The inventors have found that the resin obtained on mixing together different cyclic anhydrides, preferably an aliphatic anhydride and an aromatic anhydride in a polymer free mixture with an amine, provides a resin suitable for a mineral wool binder, which has desirable curing times.
The inventors theorize that the increased curing speed may not only be related to the combined use of cyclic anhydrides, but also to the adjustment of the pH, preferably to between 2.5 and 4.2, by employing aromatic carboxylic acids. These carboxylic acids are more acidic than aliphatic ones. Trimellitic anhydride is even more acidic due to the presence of an extra electron withdrawing group.
According to a second aspect of the present invention there is provided a binder.
According to a further aspect of the present invention there is provided a mineral fibre product.
According to yet a further aspect of the present invention there is provided a process for providing a polymer free resin for a binder suitable for binding mineral fibre products.
According to yet another use of the present invention there is provided the use of the above referred to resin in a mineral wool binder.
The invention will now be further clarified by way of the following description with reference to the examples.
Three binder compositions were made up according to the Mol.ratios as shown in table 1, whereby various accelerators were added to these compositions (see column 3 of table 1).